This invention relates in general to apparatus and a method for manufacturing rotationally symmetrical constructional parts and, in particular, to a new and useful device and method for winding a wire of non-circular cross-section over a constructional part formed by spirally wound juxtaposed tubes, which are held on a conforming supporting cone, by feeding the wire substantially perpendicular to the axis of the constructional part and maintaining a tension on the wire so that the successive turns of the wire are in close juxtaposition.
The present invention is an improvement over a non-anticipating copending application, Ser. No. 717,693, which is the parent of a non-anticipating continuation-in-part Ser. No. 872,432, now U.S. Pat. No. 4,148,121. This application and patent are incorporated by reference in the present application to show details of common structure. In the aforementioned patent and application, the construction part comprises a plurality of juxtaposed spirally-wound tubes which, in the finished state, are welded or brazed, or otherwise connected to each other along their juxtaposed surfaces, the construction part decreasing in radius from a larger end to a smaller end. The tubes forming the constructional part are initially spirally wound, in juxtaposition with each other, on a bending device, and then the bunch of tubes is removed from the bending device. The tubes are then placed in a position on a conforming mounting core and clamped together by a wire winding which is fixed thereto by means of a plurality of soldering areas. The individual tubes are thus bunched together and clamped. They are interconnected, preferably by being welded to each other at their outside edges consecutively by sectors, for which purpose the wire wrapping is removed in advance, also by sectors.
The conforming mounting core, whose external peripheral surface conforms to the internal peripheral surface of the bunched tubes, does not form part of the finished constructional part, as the latter is constituted only by the interconnected spirally-wound juxtaposed tubes. The present invention is an improvement over this, and particularly in respect to an apparatus for insuring that even with a sharper curved contour of the constructional part to be manufactured, the bunched tubes are securely and firmly pressed into contact with the mounting device the wire winding up to the connecting operation without running the risk of misadjustments of the wire winding during the winding operation.